The present exemplary embodiment relates to a chip dryer with integrated exhaust gas treatment. It finds particular application in conjunction with a scrap metal submergence device, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.
This disclosure relates to a method for the treatment of waste products, in particular, waste products of metal which are contaminated with water, oil and oleaginous cooling agents, and to an apparatus for carrying out such method.
When metals are machined, a number of waste products are automatically produced in the form of particles or chips, e.g. fillings, turnings, borings or machining scrap. In the machining of metals, for example, aluminum and aluminum alloys, oil or oil containing cooling fluids may be employed. The machined chips will therefore be contaminated with oil. In a typical situation, the borings and turnings will include, by weight, from 2 to 20 percent cutting oil.
Nonetheless, recovery of the scrap borings, turnings and chips is desirable in view of the cost of the base materials. However, the high moisture and hydrocarbon content in the material creates a dangerous situation of moisture expansion or explosion within the furnace. In addition, the hydrocarbon content will create contamination, melt loss and excessive smoking. Accordingly, direct introduction of the material into a molten metal environment is, for all practical purposes, nearly impossible.
Various attempts have been made in the industry to overcome the foregoing problems by removing the moisture and hydrocarbons from the material. One recovery process used for chips is washing of the chips with a subsequent drying process. The washers will basically dissolve the hydrocarbon leaving the chips somewhat free of the hydrocarbons but still heavy with moisture. The wet material is then dried. The use of solvents to remove the oil from the oil-coated chips works well. However, this is an expensive method and not desirable from an environmental point of view. Alternatively, centrifuge can remove both hydrocarbon content and water to a certain extent. However, this can be a time consuming and expensive process. As a further alternative, thermal dryers have been developed which uses various means of heating the products with hot air. However, to date these systems have been inefficient and not particularly environmental friendly.
The present disclosure provides a description of an improved thermal dryer apparatus to provide scrap pieces having very low hydrocarbon and water content.